FIG. 17 shows a conventional configuration of an active matrix substrate (of a pixel division system) that has a multi-pixel structure. As shown in FIG. 17, an active matrix substrate 905 includes data signal lines 915 extending in a column direction, scanning signal lines 916 extending in a row direction, storage capacitor lines 918a and 918b extending in the row direction, and pixel areas 903 partitioned by the data signal lines and the storage capacitor lines. Each scanning signal line 916 crosses a center of corresponding pixel areas 903. In each pixel area 903, first and second transistors 912a and 912b, and first and second pixel electrodes 917a and 917b are formed. Note that one storage capacitor line (918a or 918b) is provided so as to correspond to two pixel areas adjacent to each other in the column direction, and each of the storage capacitor lines (918a and 918b) is shared by two pixel areas adjacent to each other in the column direction.
In a pixel area 903, the first and second transistors 912a and 912b have a common source electrode 908 connected to a corresponding data signal line 915. The first transistor 912a has a drain electrode 909a connected to a first pixel electrode 917a via a contact hole 911a. The second transistor 912b has a drain electrode 909b connected to a second pixel electrode 917b via a contact hole 911b. Note that the scanning signal line 916 functions as a gate electrode of each of the first and second transistors 912a and 912b. 
Further, the storage capacitor line 918a overlaps the first pixel electrode 917a while the storage capacitor line 918b overlaps the second pixel electrode 917b. This forms a first storage capacitor between the storage capacitor line 918a and the first pixel electrode 917a and a second storage capacitor between the second storage capacitor line 918b and the second pixel electrode 917b. 
In a liquid crystal display device including the active matrix substrate 905, each section corresponding to the pixel area 903 forms one pixel. In one pixel, a first sub-pixel is formed so as to include the first electrode 917a and a second sub-pixel is formed so as to include the second pixel electrode 917b. In the liquid crystal display device, though a potential of a signal supplied from the data signal line 915 to the first pixel electrode 917a is the same as a potential of a signal supplied from the data signal line 915 to the second pixel electrode 917b, the potential to the first pixel electrode 917a via the first storage capacitor may be arranged to be different from the potential to the second pixel electrode 917b via the second storage capacitor by separately controlling potentials of the storage capacitor lines 918a and 918b (e.g., by controlling the potentials so that one of the potentials is pumped up while the other one of the potentials is pumped down.).
Therefore, in the liquid crystal display device, expression of gray levels is possible by arranging one pixel with use of a sub-pixel having a high luminance (bright sub-pixel) and a sub-pixel having a low luminance (dark sub-pixel). Further, dependency of gamma characteristic on a viewing angle (e.g., a phenomenon in which a screen appears whitish) can be improved.
Among active matrix substrates, there is an active matrix substrate provided with auxiliary lines (not shown) for correcting a defect such as a disconnection of a data signal line. In such an active matrix substrate, as shown in FIG. 18, a disconnection of a data line can be corrected by connecting a section subsequent to the disconnection to an auxiliary line (i.e., by supplying a signal potential via the auxiliary line) even if a disconnection of the data signal line occurs.
Patent Literature 1 is one example of a well-known document relevant to the present invention.